Page 122 - Fluid Catalytic Cracking Handbook
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i8 Fluid Catalytic Cracking Handbook
USY Zeolite
An ultrastable or a dealuminated zeolite (USY) is produced by
replacing some of the aluminum ions in the framework with silicon.
The conventional technique (Figure 3-9) includes the use of a high
temperature (1,300-1,500°F [704-816°C]) steam calcination of
HY zeolite,
NAY (13%Na O,A, 24.68 A)
c
2
NHf - EXCHANGES
4
NHY I (3%Na 90)
£
STEAM CALCINE 114OO DEG. F
USY (3%Na O,A 0* 24,50A!
JVH.+ . EXCHANGES
LOW-SODA USY (<!%NaO)
Figure 3-9. Synthesis of USY zeolite (NAY),
